Uninterruptible power supply

ABSTRACT

In an uninterruptible power supply, first connection members that connect input side-switches of a plurality of uninterruptible power supply modules to each other and that connect output-side switches of the plurality of uninterruptible power supply modules to each other, and second connection members connected in parallel to the first connection members are disposed at positions accessible from a front side of the uninterruptible power supply modules.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of PCT application PCT/JP2017/024500,filed on Jul. 4, 2017, which is based upon and claims priority ofJapanese patent application No. 2016-158142, filed on Aug. 10, 2016, theentire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to an uninterruptible power supply, andmore particularly, it relates to an uninterruptible power supplyincluding a plurality of uninterruptible power supply modules.

Description of the Background Art

An uninterruptible power supply including a plurality of uninterruptiblepower supply modules is known in general. Such a power supply unit isdisclosed in Japanese Patent No. 5732134.

Japanese Patent No. 5732134 discloses an uninterruptible power supplyincluding a plurality of uninterruptible power supply modules connectedin parallel to a load. This uninterruptible power supply includes wiring(hereinafter referred to as input-side connection wiring) that connectsthe input sides of the plurality of uninterruptible power supply modulesto each other and wiring (hereinafter referred to as output-sideconnection wiring) that connects the output sides of the plurality ofuninterruptible power supply modules to each other.

In the conventional uninterruptible power supply as described inJapanese Patent No. 5732134, after the plurality of uninterruptiblepower supply modules is disposed, the input sides of the plurality ofuninterruptible power supply modules are connected to each other by theinput-side connection wiring, and the output sides of the plurality ofuninterruptible power supply modules are connected to each other by theoutput-side connection wiring. Furthermore, in the conventionaluninterruptible power supply as described in Japanese Patent No.5732134, the input-side connection wiring and the output-side connectionwiring may be provided on the back side of the uninterruptible powersupply modules (housings that house the uninterruptible power supplymodules).

However, in the conventional uninterruptible power supply in which theinput-side connection wiring and the output-side connection wiring areprovided on the back side of the uninterruptible power supply modules(the housings that house the uninterruptible power supply modules), awork area for attaching the input-side connection wiring and theoutput-side connection wiring (connection member) is required betweenthe uninterruptible power supply modules and the wall surface when theuninterruptible power supply modules are disposed in the vicinity of thewall surface. That is, a work area required to install theuninterruptible power supply disadvantageously becomes large.

SUMMARY OF THE INVENTION

The present invention has been proposed in order to solve theaforementioned problem, and an object of the present invention is toprovide an uninterruptible power supply capable of significantlyreducing or preventing an increase in the size of a work area requiredfor installation.

An uninterruptible power supply according to an aspect of the presentinvention includes a plurality of uninterruptible power supply modulesincluding input-side switches into which AC power is input from an ACpower source, power converters connected to the input-side switches, andoutput-side switches that output AC power received from the powerconverters, a first connection member that connects the inputside-switches of the plurality of uninterruptible power supply modulesto each other and a first connection member that connects theoutput-side switches of the plurality of uninterruptible power supplymodules to each other, and second connection members connected inparallel to the first connection members. The first connection membersand the second connection members are disposed at positions accessiblefrom a front side of the uninterruptible power supply modules.

In the uninterruptible power supply according to this aspect of thepresent invention, as described above, the connection member thatconnects the input-side switches of the plurality of uninterruptiblepower supply modules to each other and the connection member thatconnects the output-side switches of the plurality of uninterruptiblepower supply modules to each other are disposed at the positionsaccessible from the front side of housings. Thus, the connection membersare disposed at the positions accessible from the front side of thehousings, and hence even when the uninterruptible power supply modulesare disposed in the vicinity of the wall surface, it is not necessary toprovide a work area for attaching the connection members between theuninterruptible power supply modules and the wall surface. Consequently,it is possible to significantly reduce or prevent an increase in thesize of a work area required to install the uninterruptible powersupply. Furthermore, the uninterruptible power supply can be installedclose to the wall, and hence a space on the front side of theuninterruptible power supply can be effectively utilized.

In addition, unlike the case where the connection members are providedon the back side of the uninterruptible power supply modules, and theconnection members are attached in a relatively small work area betweenthe uninterruptible power supply modules and the wall surface, theworkability of attaching the connection members can be improved.Furthermore, even when the amount of current that flows through theconnection members increases, the current capacity of the connectionmembers can be easily increased simply by providing the secondconnection members in parallel to the first connection members. When theamount of current that flows through the connection members isrelatively small, the connection members are configured to include onlythe first connection members such that it is possible to significantlyreduce or prevent an increase in the size of the connection members.

In the aforementioned uninterruptible power supply according to thisaspect, the second connection members each preferably have a currentcapacity proportional to a number of the uninterruptible power supplymodules.

In the aforementioned uninterruptible power supply according to thisaspect, the second connection members in the uninterruptible powersupply modules connected closer to the AC power source preferably havelarger current capacities.

In the aforementioned uninterruptible power supply according to thisaspect, the first connection members preferably include an input-sideconnection member that connects the input-side switches to each other,and an output-side connection member that connects the output-sideswitches to each other, and the input-side connection member and theoutput-side connection member are preferably disposed in any of upperportions of the uninterruptible power supply modules, lower portions ofthe uninterruptible power supply modules, and middle portions of theuninterruptible power supply modules. According to this configuration,the input-side connection member and the output-side connection memberare disposed above, below, or between the devices that theuninterruptible power supply modules include, such that the input-sideconnection member and the output-side connection member can be easilyexposed on the front side of the housings.

In this case, the power converters are preferably disposed in the lowerportions of the uninterruptible power supply modules, the input-sideswitches and the output-side switches are preferably disposed above thepower converters, and the input-side connection member and theoutput-side connection member are preferably disposed in the upperportions of the uninterruptible power supply modules. According to thisconfiguration, unlike the case where the input-side connection memberand the output-side connection member are disposed in the lower portions(in the vicinity of the ground) of the uninterruptible power supplymodules, a worker can attach the input-side connection member and theoutput-side connection member without losing his or her balance.Consequently, the workability of attaching the input-side connectionmember and the output-side connection member can be improved.

In the aforementioned uninterruptible power supply according to thisaspect, the plurality of uninterruptible power supply modules preferablyincludes a first uninterruptible power supply module, a seconduninterruptible power supply module, and a third uninterruptible powersupply module disposed in order from the AC power supply side, each ofconnection members respectively connected to the input-side switches andthe output-side switches of the third uninterruptible power supplymodule preferably includes the first connection member, each ofconnection members respectively connected to the input-side switches andthe output-side switches of the second uninterruptible power supplymodule preferably includes the first connection member and a secondconnection member, and each of connection members respectively connectedto the input-side switches and the output-side switches of the firstuninterruptible power supply module preferably includes the firstconnection member and a plurality of the second connection members. Whenthe input-side switches of the first uninterruptible power supplymodule, the second uninterruptible power supply module, and the thirduninterruptible power supply module are connected to each other by theconnection member, and the output-side switches of the firstuninterruptible power supply module, the second uninterruptible powersupply module, and the third uninterruptible power supply module areconnected to each other by the connection member, current that flows tothe input-side switches of the uninterruptible power supply module(s)disposed downstream of current flow as well as current that flows to itsown input-side switches flows through the connection member connected tothe input-side switches of the uninterruptible power supply module(s)disposed upstream of the current flow. Similarly, current that flowsfrom the output-side switches of the uninterruptible power supplymodule(s) disposed upstream of current flow as well as current thatflows from its own output-side switches flows through the connectionmember connected to the output-side switches of the uninterruptiblepower supply module(s) disposed downstream of the current flow.Therefore, with the above configuration, the current capacity of theconnection member disposed upstream of input power (downstream of outputpower) is larger than the current capacity of the connection memberdisposed downstream of input power (upstream of output power), and henceit is possible to significantly reduce or prevent flow of current thatexceeds the current capacity.

The aforementioned uninterruptible power supply according to this aspectpreferably further includes fastener members that fasten the input-sideswitches and the output-side switches to the first connection members,and the second connection members each preferably have a bent shape soas to avoid the fastener members. According to this configuration, thefastener members are allowed to escape due to the bent shape of thesecond connection members, and hence mechanical interference between thefastener members and the second connection members can be prevented.

The aforementioned uninterruptible power supply according to this aspectpreferably further includes fastener members that fasten the input-sideswitches and the output-side switches to the first connection members,and the second connection members each preferably include at least oneof holes and notches through which the fastener members pass. Accordingto this configuration, the fastener members are allowed to escape due tothe holes or the notches, and hence mechanical interference between thefastener members and the second connection members can be prevented.Furthermore, the fastener members pass through at least one of the holesand the notches such that the second connection members can be disposedso as to overlap the first connection members without being bent. Thus,it is possible to significantly reduce or prevent an increase in thesize of the connection members.

The foregoing and other objects, features, aspects and advantages of thepresent invention will become more apparent from the following detaileddescription of the present invention when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a circuit configuration diagram of an uninterruptible powersupply according to a first embodiment of the present invention;

FIG. 2 is a front view schematically showing the uninterruptible powersupply according to the first embodiment of the present invention;

FIG. 3 is a side view of a connection member of the uninterruptiblepower supply according to the first embodiment of the present invention;

FIG. 4 is a perspective view of an input-side connection member of theuninterruptible power supply according to the first embodiment of thepresent invention;

FIG. 5 is a perspective view of an output-side connection member of theuninterruptible power supply according to the first embodiment of thepresent invention;

FIG. 6 is a perspective view of an input-side connection member of anuninterruptible power supply according to a second embodiment of thepresent invention;

FIG. 7 is a perspective view of an output-side connection member of theuninterruptible power supply according to the second embodiment of thepresent invention;

FIG. 8 is a front view schematically showing an uninterruptible powersupply according to a first modified example of the first and secondembodiments of the present invention; and

FIG. 9 is a front view schematically showing an uninterruptible powersupply according to a second modified example of the first and secondembodiments of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention are hereinafter described withreference to the drawings.

First Embodiment

(Circuit Configuration)

First, the circuit configuration of an uninterruptible power supply 100according to a first embodiment is described with reference to FIG. 1.

As shown in FIG. 1, the uninterruptible power supply 100 includes aplurality of uninterruptible power supply modules 1 (a firstuninterruptible power supply module 1 a, a second uninterruptible powersupply module 1 b, and a third uninterruptible power supply module 1 c)and an input/output module 2 (I/O module). The plurality ofuninterruptible power supply modules 1 is disposed in parallel to eachother. As shown in FIG. 2, the plurality of uninterruptible power supplymodules 1 (the first uninterruptible power supply module 1 a, the seconduninterruptible power supply module 1 b, and the third uninterruptiblepower supply module 1 c) is disposed adjacent to each other in aright-left direction. Furthermore, the input/output module 2 is disposedadjacent to the uninterruptible power supply modules 1 in the right-leftdirection (direction X). For example, in FIG. 2, the input/output module2 is disposed on the left side (arrow X1 direction side) of theplurality of uninterruptible power supply modules 1. In theuninterruptible power supply 100, the plurality of uninterruptible powersupply modules 1 and the input/output module 2 are connected to eachother via connection members 40 (an input-side connection member 50 andan output-side connection member 60) described later.

As shown in FIG. 1, an uninterruptible power supply module 1 includesinput-side switches 11. The input-side switches 11 receive AC power froman AC power source 3. An input-side switch 11 is provided for each phase(U-phase, V-phase, and W-phase), and a total of three input-sideswitches 11 are provided in the uninterruptible power supply module 1.

The uninterruptible power supply module 1 includes input filters 12. Theinput filters 12 are connected to the input-side switches 11. An inputfilter 12 is provided for each phase, and a total of three input filters12 are provided in the uninterruptible power supply module 1.

The uninterruptible power supply module 1 includes a power converter 13.The power converter 13 is connected to the input-side switches 11 viathe input filters 12. The power converter 13 includes a rectifiercircuit 13 a, a chopper circuit 13 b, and an inverter circuit 13 c. Inaddition, the power converter 13 includes elements made of siliconcarbide (SiC). Thus, as compared with the case where the power converter13 includes elements made of silicon, the power loss of the powerconverter 13 is reduced, and the amount of heat generation due to thepower loss is reduced.

The rectifier circuit 13 a has a function of converting the AC powerinput into the power converter 13 into DC power. The chopper circuit 13b is configured as a three-level chopper circuit, for example. That is,the chopper circuit 13 b has a function of transforming the voltage ofthe DC power obtained by conversion by the rectifier circuit 13 a andoutputting the voltage as three levels of voltage. The DC power, thevoltage of which has been transformed by the chopper circuit 13 b, isconnected to a battery 4 via a DC reactor 14 and a DC bus 14 a.

The uninterruptible power supply module 1 includes output filters 15.The output filters 15 are connected to the inverter circuit 13 c of thepower converter 13. An output filter 15 is provided for each phase, anda total of three output filters 15 are provided in the uninterruptiblepower supply module 1.

The uninterruptible power supply module 1 includes output-side switches16. The output-side switches 16 output AC power received from the powerconverter 13 via the output filters 15. An output-side switch 16 isprovided for each phase, and a total of three output-side switches 16are provided in the uninterruptible power supply module 1.

The uninterruptible power supply module 1 includes input-side filtercapacitors 17 provided between the input-side switches 11 and the inputfilters 12. The uninterruptible power supply module 1 further includesoutput-side filter capacitors 18 provided between the output-sideswitches 16 and the output filters 15.

The input-side switches 11, the input filters 12, the power converter13, the output filters 15, the output-side switches 16, the input-sidefilter capacitors 17, and the output-side filter capacitors 18 areincluded in each of the plurality of uninterruptible power supplymodules 1.

The uninterruptible power supply 100 includes a direct transmissioncircuit 22. The direct transmission circuit 22 is provided in theinput/output module 2, and is connected to the AC power source 3 and theoutput sides (load 5 sides) of the plurality of uninterruptible powersupply modules 1. The direct transmission circuit 22 includes thyristorswitches 22 a and mechanical switches 22 b connected in series to thethyristor switches 22 a. The direct transmission circuit 22 includesmechanical switches 22 c connected in parallel to the thyristor switches22 a and the mechanical switches 22 b connected in series to each other.

(Configuration Relating to Arrangement of Devices)

Next, the configuration relating to the arrangement of devices insidehousings 30 of the uninterruptible power supply modules 1 is describedwith reference to FIG. 2.

As shown in FIG. 2, the uninterruptible power supply 100 includes aplurality of housings 30 that houses the plurality of uninterruptiblepower supply modules 1, respectively. The housings 30 each have a boxshape. The input-side switches 11, the input filters 12, the powerconverter 13, the DC reactor 14, the output filters 15, the output-sideswitches 16, the input-side filter capacitors 17, and the output-sidefilter capacitors 18 are housed inside each of the housings 30.Specifically, each of the housings 30 houses the input-side switches 11,the input-side filter capacitors 17, the input filters 12, the powerconverter 13 (the rectifier circuit 13 a and the chopper circuit 13 b)in this order from the upper side (upper surface 31) toward the lowerside (in an arrow Z2 direction). Furthermore, each of the housings 30houses the power converter 13 (inverter circuit 13 c), the outputfilters 15, the output-side filter capacitors 18, and the output-sideswitches 16 in this order in an upward direction (arrow Z1 direction).

According to the first embodiment, the uninterruptible power supply 100includes a connection member 40 that connects the input-side switches 11of the plurality of uninterruptible power supply modules 1 to each otherand a connection member 40 that connects the output-side switches 16 ofthe plurality of uninterruptible power supply modules 1 to each other.The connection members 40 are disposed at positions accessible from thefront side (arrow Y1 direction side) of the housings 30. The positionsaccessible from the front side of the housings 30 denote positions in anarea corresponding to the length of the arm of a general worker from thefront ends of the housings 30 toward the inside of the housings 30. Thatis, a user (worker) can attach and maintain the connection members 40from the front side of the housings 30. The “front side” denotes theside opposite to the wall side (back side) of the uninterruptible powersupply 100 when the uninterruptible power supply 100 is disposed on thewall or the like. The connection members 40 are each made of a memberhaving conductivity such as copper.

The housings 30 include openable and closable front doors (not shown) soas to expose the front side (arrow Y1 direction side). The connectionmembers 40 are disposed at the positions accessible from the front sideof the housings 30 in a state where the front doors are opened.

According to the first embodiment, the connection members 40 include theinput-side connection member 50 that connects the input-side switches 11to each other and the output-side connection member 60 that connects theoutput-side switches 16 to each other. The input-side connection member50 and the output-side connection member 60 are disposed in upperportions of the uninterruptible power supply modules 1 in the housings30. As described above, the power converter 13 is disposed in a lowerportion of each of the housings 30, and the input-side switches 11 andthe output-side switches 16 are disposed above the power converter 13.Both of the input-side connection member 50 and the output-sideconnection member 60 are disposed in the upper portions of theuninterruptible power supply modules 1 (above the input-side switches 11and the output-side switches 16).

As shown in FIG. 3, the input-side connection member 50 is disposedabove the output-side connection member 60. That is, connectionterminals 11 a of the input-side switches 11 extend upward beyondconnection terminals 16 a of the output-side switches 16. Thus, theinput-side connection member 50 connected to the connection terminals 11a of the input-side switches 11 is disposed above the output-sideconnection member 60 connected to the connection terminals 16 a of theoutput-side switches 16. Furthermore, the input-side connection member50 is disposed vertically above the output-side connection member 60.

The input-side connection member 50 is connected to the inside of theinput/output module 2, and transmits AC power to each of the input-sideswitches 11 via the input/output module 2. The output-side connectionmember 60 is connected to the inside of the input/output module 2, andsupplies AC power from each of the output-side switches 16 to the load 5via the input/output module 2.

According to the first embodiment, as shown in FIGS. 3 and 4, each ofthe connection members 40 includes at least first connection members 41of the first connection members 41 that connect the input-side switches11 of the plurality of uninterruptible power supply modules 1 to eachother or that connect the output-side switches 16 of the plurality ofuninterruptible power supply modules 1 to each other and secondconnection members 42 connected in parallel to the first connectionmembers 41 and that increase the capacity of current that flows betweenthe input-side switches 11 or the capacity of current that flows betweenthe output-side switches 16.

Specifically, as shown in FIGS. 3 and 4, the plurality ofuninterruptible power supply modules 1 includes the firstuninterruptible power supply module 1 a, the second uninterruptiblepower supply module 1 b, and the third uninterruptible power supplymodule 1 c disposed in order from the AC power source 3 (input/outputmodule 2) side. As shown in FIGS. 4 and 5, a connection member(input-side connection member 50 c) connected to the input-side switches11 of the third uninterruptible power supply module 1 c includes a firstconnection member 41 (first connection member 41 c). Furthermore, aconnection member (output-side connection member 60 c) connected to theoutput-side switches 16 of the third uninterruptible power supply module1 c includes a first connection member 41 (first connection member 41f). That is, a second connection member 42 is not included in theinput-side connection member 50 c or the output-side connection member60 c of the third uninterruptible power supply module 1 c.

A connection member (input-side connection member 50 b) connected to theinput-side switches 11 of the second uninterruptible power supply module1 b includes a first connection member 41 (first connection member 41 b)and a second connection member 42 (second connection member 42 a). Aconnection member (output-side connection member 60 b) connected to theoutput-side switches 16 of the second uninterruptible power supplymodule 1 b includes a first connection member 41 (first connectionmember 41 e) and a second connection member 42 (second connection member42 d). That is, each of the input-side connection member 50 b and theoutput-side connection member 60 b of the second uninterruptible powersupply module 1 b includes one first connection member 41 and one secondconnection member 42.

A connection member (input-side connection member 50 a) connected to theinput-side switches 11 of the first uninterruptible power supply module1 a includes a first connection member 41 (first connection member 41 a)and a plurality of second connection members 42 (second connectionmembers 42 b and 42 c). A connection member (output-side connectionmember 60 a) connected to the output-side switches 16 of the firstuninterruptible power supply module 1 a includes a first connectionmember 41 (first connection member 41 d) and a plurality of secondconnection members 42 (second connection members 42 e and 42 f).Specifically, each of the input-side connection member 50 a and theoutput-side connection member 60 a of the first uninterruptible powersupply module 1 a includes one first connection member 41 and two secondconnection members 42.

The uninterruptible power supply 100 receives three-phase (U-phase,V-phase, and W-phase) AC power and outputs three-phase AC power. Theuninterruptible power supply 100 includes three input-side connectionmembers 50 a, three input-side connection members 50 b, three input-sideconnection members 50 c, three output-side connection members 60 a,three output-side connection members 60 b, and three output-sideconnection members 60 c (three-phase three-wire system).

According to the first embodiment, each of the input-side switches 11and the output-side switches 16 and the first connection members 41 arefixed (fastened) by bolts 70. The second connection members 42 connectedin parallel to the first connection members 41 each have a bent shape soas to avoid the bolts 70. The bolts 70 are examples of a “fastenermember” in the claims.

(Detailed Structure of Input-Side Connection Member)

The detailed structure of the input-side connection member 50 connectedto the input-side switches 11 is now described.

As shown in FIG. 4, the AC power source 3 side and the first connectionmember 41 a of the first uninterruptible power supply module 1 a areconnected to each other by a connection plate 43 a. The first connectionmember 41 a of the first uninterruptible power supply module 1 a and thefirst connection member 41 b of the second uninterruptible power supplymodule 1 b are connected to each other by a connection plate 43 b. Thefirst connection member 41 b of the second uninterruptible power supplymodule 1 b and the first connection member 41 c of the thirduninterruptible power supply module 1 c are connected to each other by aconnection plate 43 c. The connection plates 43 a, 43 b, and 43 c arefixed by bolts 70. The second connection member 42 a is connected so asto straddle the first connection member 41 b of the seconduninterruptible power supply module 1 b and the connection plate 43 bwhile avoiding the bolts 70. The second connection member 42 b isconnected so as to straddle the first connection member 41 a of thefirst uninterruptible power supply module 1 a and the connection plate43 a while avoiding the bolts 70. The second connection member 42 c isconnected so as to straddle the connection plate 43 a and the connectionplate 43 b while avoiding the bolts 70 and so as to overlap the upperside of the second connection member 42 b. The second connection members42 a, 42 b, and 42 c each have a bent shape (substantially U-shape).

(Detailed Structure of Output-Side Connection Member)

The detailed structure of the output-side connection member 60 connectedto the output-side switches 16 is now described.

As shown in FIG. 5, the load 5 side and the first connection member 41 dof the first uninterruptible power supply module 1 a are connected toeach other by a connection plate 43 d. The first connection member 41 dof the first uninterruptible power supply module 1 a and the firstconnection member 41 e of the second uninterruptible power supply module1 b are connected to each other by a connection plate 43 e. The firstconnection member 41 e of the second uninterruptible power supply module1 b and the first connection member 41 f of the third uninterruptiblepower supply module 1 c are connected to each other by a connectionplate 43 f. The connection plates 43 d, 43 e, and 43 f are fixed bybolts 70. The second connection member 42 d is connected so as tostraddle the connection plate 43 e and the connection plate 43 f whileavoiding the bolts 70. The second connection member 42 e is connected soas to straddle the connection plate 43 d and the connection plate 43 ewhile avoiding the bolts 70. The second connection member 42 f isconnected so as to straddle the connection plate 43 d and the connectionplate 43 e while avoiding the bolts 70 and so as to overlap the upperside of the second connection member 42 e. The second connection members42 d, 42 e, and 42 f each have a bent shape (substantially U-shape).

(Effects of First Embodiment)

According to the first embodiment, the following effects can beobtained.

According to the first embodiment, as described above, the connectionmember 40 that connects the input-side switches 11 of the plurality ofuninterruptible power supply modules 1 to each other and the connectionmember 40 that connects the output-side switches 16 of the plurality ofuninterruptible power supply modules 1 to each other are disposed at thepositions accessible from the front side of the housings 30. Thus, theconnection members 40 are disposed at the positions accessible from thefront side of the housings 30, and hence even when the uninterruptiblepower supply modules 1 are disposed in the vicinity of the wall surface,it is not necessary to provide a work area for attaching the connectionmembers 40 between the uninterruptible power supply modules 1 and thewall surface. Consequently, it is possible to significantly reduce orprevent an increase in the size of a work area required to install theuninterruptible power supply 100. Furthermore, the uninterruptible powersupply 100 can be installed close to the wall, and hence a space on thefront side of the uninterruptible power supply 100 can be effectivelyutilized.

In addition, unlike the case where the connection members 40 areprovided on the back side of the uninterruptible power supply modules 1,and the connection members 40 are attached in a relatively small workarea between the uninterruptible power supply modules 1 and the wallsurface, the workability of attaching the connection members 40 can beimproved.

According to the first embodiment, as described above, the powerconverter 13 is disposed in the lower portion of each of the housings30, the input-side switches 11 and the output-side switches 16 aredisposed above the power converter 13, and the input-side connectionmember 50 and the output-side connection member 60 are disposed in theupper portions of the uninterruptible power supply modules 1. Thus, theinput-side connection member 50 and the output-side connection member 60are disposed above the devices that the uninterruptible power supplymodules 1 include such that the input-side connection member 50 and theoutput-side connection member 60 can be easily exposed on the front sideof the housings 30. Furthermore, unlike the case where the input-sideconnection member 50 and the output-side connection member 60 aredisposed in lower portions (in the vicinity of the ground) of theuninterruptible power supply modules 1, the worker can attach theinput-side connection member 50 and the output-side connection member 60without losing his or her balance. Consequently, the workability ofattaching the input-side connection member 50 and the output-sideconnection member 60 can be improved.

According to the first embodiment, as described above, each of theconnection members 40 includes at least the first connection members 41of the first connection members 41 that connect the input-side switches11 of the plurality of uninterruptible power supply modules 1 to eachother or that connect the output-side switches 16 of the plurality ofuninterruptible power supply modules 1 to each other and the secondconnection members 42 connected in parallel to the first connectionmembers 41 and that increase the capacity of current that flows betweenthe input-side switches 11 or the current capacity of current that flowsbetween the output-side switches 16. Thus, even when the amount ofcurrent that flows through the connection members 40 increases, thecurrent capacity of the connection members 40 can be easily increasedsimply by providing the second connection members 42 in parallel to thefirst connection members 41. In addition, when the amount of currentthat flows through the connection members 40 is relatively small, theconnection members 40 are configured to include only the firstconnection members 41 such that it is possible to significantly reduceor prevent an increase in the size of the connection members 40.

According to the first embodiment, as described above, the connectionmembers (the input-side connection member 50 c and the output-sideconnection member 60 c) of the third uninterruptible power supply module1 c respectively connected to the input-side switches 11 and theoutput-side switches 16 include the first connection members 41, theconnection members (the input-side connection member 50 b and theoutput-side connection member 60 b) of the second uninterruptible powersupply module 1 b respectively connected to the input-side switches 11and the output-side switches 16 include the first connection members 41and the second connection members 42, and the connection members (theinput-side connection member 50 a and the output-side connection member60 a) of the first uninterruptible power supply module 1 a respectivelyconnected to the input-side switches 11 and the output-side switches 16include the first connection members 41 and the second connectionmembers 42. When the input-side switches 11 of the first uninterruptiblepower supply module 1 a, the second uninterruptible power supply module1 b, and the third uninterruptible power supply module 1 c are connectedto each other by the connection member 40, and the output-side switches16 of the first uninterruptible power supply module 1 a, the seconduninterruptible power supply module 1 b, and the third uninterruptiblepower supply module 1 c are connected to each other by the connectionmember 40, the current that flows to the input-side switches 11 of theuninterruptible power supply module(s) 1 disposed downstream of currentflow as well as the current that flows to its own input-side switches 11flows through the connection member connected to the input-side switches11 of the uninterruptible power supply module(s) 1 disposed upstream ofthe current flow. Similarly, the current that flows from the output-sideswitches 16 of the uninterruptible power supply module(s) 1 disposedupstream of current flow as well as the current that flows from its ownoutput-side switches 16 flows through the connection member connected tothe output-side switches 16 of the uninterruptible power supplymodule(s) 1 disposed downstream of the current flow. Therefore, with theabove configuration, the current capacity of the connection memberdisposed upstream of input power (downstream of output power) is largerthan the current capacity of the connection member disposed downstreamof input power (upstream of output power), and hence it is possible tosignificantly reduce or prevent flow of current that exceeds the currentcapacity.

According to the first embodiment, as described above, theuninterruptible power supply 100 includes the bolts 70 that fasten theinput-side switches 11 and the output-side switches 16 to the firstconnection members 41. Furthermore, the second connection members 42connected in parallel to the first connection members 41 each have abent shape so as to avoid the bolts 70. Thus, the bolts 70 are allowedto escape due to the bent shape of the second connection members 42, andhence mechanical interference between the bolts 70 and the secondconnection members 42 can be prevented.

Second Embodiment

The configuration of an uninterruptible power supply 110 according to asecond embodiment is now described with reference to FIGS. 6 and 7. Inthe uninterruptible power supply 110 according to the second embodiment,at least one of holes 144 and notches 145 are provided in connectionmembers 140.

(Detailed Structure of Input-Side Connection Member)

First, the detailed structure of a connection member 140 (input-sideconnection member 150) connected to input-side switches 11 is described.

As shown in FIG. 6, a connection plate 143 a connects a first connectionmember 41 a of a first uninterruptible power supply module 1 a to afirst connection member 41 b of a second uninterruptible power supplymodule 1 b. A connection plate 143 b connects the first connectionmember 41 b of the second uninterruptible power supply module 1 b to afirst connection member 41 c of a third uninterruptible power supplymodule 1 c. A second connection member 142 (142 a) connects the firstconnection member 41 b of the second uninterruptible power supply module1 b to the connection plate 143 a. The second connection member 142 a isprovided in parallel to the first connection member 41 b of the seconduninterruptible power supply module 1 b, and has a bent shape(substantially U-shape).

A second connection member 142 (142 b) is provided in parallel to thefirst connection member 41 a so as to overlap the first connectionmember 41 a above the first connection member 41 a of the firstuninterruptible power supply module 1 a. According to the secondembodiment, the second connection member 142 b connected in parallel tothe first connection member 41 a includes the holes 144 through whichbolts 70 (bolts 70 that connect the input-side switches 11 to the firstconnection member 41 a) pass. A plurality of holes 144 is provided inone second connection member 142 b so as to correspond to the number ofbolts 70. Furthermore, the second connection member 142 b has a flatplate shape (rectangular plate shape). That is, the bolts 70 arepenetrated (are allowed to escape) due to the holes 144, and hence it isnot necessary to bend the second connection member 142 b unlike thefirst embodiment.

(Detailed Structure of Output-Side Connection Member)

Next, the detailed structure of a connection member 140 (output-sideconnection member 160) connected to output-side switches 16 isdescribed.

As shown in FIG. 7, a second connection member 142 (142 c) is providedin parallel to a first connection member 41 e of the seconduninterruptible power supply module 1 b. The second connection member142 c has a substantially U-shape.

A second connection member 142 (142 d) is provided in parallel to afirst connection member 41 d of the first uninterruptible power supplymodule 1 a. According to the second embodiment, the second connectionmember 142 d connected in parallel to the first connection member 41 dincludes the notches 145 through which bolts 70 (bolts 70 that connectthe output-side switches 16 to the first connection member 41 d) pass. Aplurality of notches 145 is provided in one second connection member 142d so as to correspond to the number of bolts 70. Furthermore, the secondconnection member 142 d has a flat plate shape (rectangular plateshape). That is, the bolts 70 are penetrated (are allowed to escape) dueto the notches 145, and hence it is not necessary to bend the secondconnection member 142 d unlike the first embodiment.

(Effects of Second Embodiment)

According to the second embodiment, the following effects can beobtained.

According to the second embodiment, as described above, the secondconnection members 142 connected in parallel to the first connectionmembers 41 include at least one of the holes 144 and the notches 145through which the bolts 70 pass. Thus, the bolts 70 are allowed toescape due to the holes 144 or the notches 145, and hence mechanicalinterference between the bolts 70 and the second connection members 142can be prevented. Furthermore, the bolts 70 pass through at least one ofthe holes 144 and the notches 145 such that the second connectionmembers 142 can be disposed so as to overlap the first connectionmembers 41 without being bent. Thus, it is possible to significantlyreduce or prevent an increase in the size of the connection members 140.

Modified Examples

The embodiments disclosed this time must be considered as illustrativein all points and not restrictive. The range of the present invention isnot shown by the above description of the embodiments but by the scopeof claims for patent, and all modifications (modified examples) withinthe meaning and range equivalent to the scope of claims for patent arefurther included.

For example, while the input-side connection members and the output-sideconnection members are disposed in the upper portions of theuninterruptible power supply modules in the housings in each of theaforementioned first and second embodiments, the present invention isnot restricted to this. For example, as in an uninterruptible powersupply 200 according to a first modified example shown in FIG. 8, aninput-side connection member 202 may be disposed in upper portions ofuninterruptible power supply modules 201, and an output-side connectionmember 203 may be disposed in lower portions of the uninterruptiblepower supply modules 201. In this case, input-side switches 11, inputfilters 12, rectifier circuits 13 a, chopper circuits 13 b, DC reactors14, inverter circuits 13 c, output filters 15, and output-side switches16 are disposed in this order from the upper side toward the lower side(in an arrow Z2 direction).

As in an uninterruptible power supply 210 according to a second modifiedexample shown in FIG. 9, an input-side connection member 212 and anoutput-side connection member 213 may be disposed between upper portionsand lower portions of uninterruptible power supply modules 211 (in thevicinity of middle portions, for example). That is, the input-sideconnection member 212 and the output-side connection member 213 may bedisposed between any of input-side switches 11, input filters 12, powerconverters 13, DC reactors 14, output filters 15, and output-sideswitches 16, which the uninterruptible power supply 210 includes.Alternatively, both the input-side connection member and the output-sideconnection member may be disposed in lower portions of theuninterruptible power supply modules.

While the third uninterruptible power supply module includes only thefirst connection member (the number of the second connection members iszero), the second uninterruptible power supply module includes one firstconnection member and one second connection member, and the firstuninterruptible power supply module includes one first connection memberand two second connection members in the aforementioned firstembodiment, the present invention is not restricted to this. Accordingto the present invention, the number of the second connection members isadjusted in accordance with the magnitude of the current that flowsthrough the connection member(s). That is, when the current that flowsthrough the connection member(s) is relatively large, the number of thesecond connection members is increased, and when the current that flowsthrough the connection member(s) is relatively small, the number of thesecond connection members is decreased (or is decreased to zero).

While the three uninterruptible power supply modules are provided in theuninterruptible power supply in each of the aforementioned first andsecond embodiments, the present invention is not restricted to this. Forexample, two, or four or more uninterruptible power supply modules maybe provided in the uninterruptible power supply.

While the second connection members each have a substantially U-shape soas to avoid the bolts in the aforementioned first embodiment, thepresent invention is not restricted to this. According to the presentinvention, the second connection members each may have any shape as longas the shape allows the second connection members to avoid the bolts.For example, the second connection members each may have an arcuateshape.

While the second connection member having a substantially U-shape andthe second connection member having a flat plate shape and including theholes or the notches are provided (mixed) in the aforementioned secondembodiment, the present invention is not restricted to this. Forexample, only second connection members each having a flat plate shapeand including holes or notches may be provided.

While the uninterruptible power supply is of a three-phase three-wiresystem (that is, three input-side connection members and threeoutput-side connection members are provided for each uninterruptiblepower supply module) in each of the aforementioned first and secondembodiments, the present invention is not restricted to this. Forexample, the present invention may be applied to an uninterruptiblepower supply of a three-phase four-wire system. In this case, fourinput-side connection members and four output-side connection membersare provided for each uninterruptible power supply module.

What is claimed is:
 1. An uninterruptible power supply comprising: a plurality of uninterruptible power supply modules including input-side switches into which AC power is adapted to be input from an AC power source, power converters connected to the input-side switches, and output-side switches that output AC power received from the power converters; first connection members that connect the input side-switches of the plurality of uninterruptible power supply modules to each other and that connect the output-side switches of the plurality of uninterruptible power supply modules to each other; second connection members connected electrically in parallel to the first connection members and stacked on the first connection members; and fastener members that fasten the input-side switches and the output-side switches to the first connection members, respectively, wherein the first connection members and the second connection members are disposed at positions accessible from front sides of the plurality of uninterruptible power supply modules, and at least one of the second connection members has a bent shape so as to avoid the fastener members.
 2. The uninterruptible power supply according to claim 1, wherein the second connection members each have a current capacity proportional to a number of the uninterruptible power supply modules.
 3. The uninterruptible power supply according to claim 1, wherein the second connection members in the uninterruptible power supply modules connected closer to the AC power source have larger current capacities.
 4. The uninterruptible power supply according to claim 1, wherein the first connection members include input-side connection members that connect the input-side switches to each other, and output-side connection members that connect the output-side switches to each other, and the input-side connection members and the output-side connection members are disposed in any of upper portions of the uninterruptible power supply modules, lower portions of the uninterruptible power supply modules, and middle portions of the uninterruptible power supply modules.
 5. The uninterruptible power supply according to claim 4, wherein the power converters are disposed in the lower portions of the uninterruptible power supply modules, the input-side switches and the output-side switches are disposed above the power converters, and the input-side connection members and the output-side connection members are disposed in the upper portions of the uninterruptible power supply modules.
 6. The uninterruptible power supply according to claim 1, wherein the plurality of uninterruptible power supply modules includes a first uninterruptible power supply module, a second uninterruptible power supply module, and a third uninterruptible power supply module adapted to be disposed in order from the AC power supply side, each of connection members respectively connected to input-side switches and output-side switches of the third uninterruptible power supply module includes the first connection member, each of connection members respectively connected to input-side switches and output-side switches of the second uninterruptible power supply module includes the first connection member and the second connection member, and each of connection members respectively connected to input-side switches and output-side switches of the first uninterruptible power supply module includes the first connection member and a plurality of the second connection members.
 7. An uninterruptible power supply comprising: a plurality of uninterruptible power supply modules including input-side switches into which AC power is adapted to be input from an AC power source, power converters connected to the input-side switches, and output-side switches that output AC power received from the power converters; first connection members that connect the input side-switches of the plurality of uninterruptible power supply modules to each other and that connect the output-side switches of the plurality of uninterruptible power supply modules to each other; second connection members connected electrically in parallel to the first connection members and stacked on the first connection members; and fastener members that fasten the input-side switches and the output-side switches to the first connection members, respectively, wherein the first connection members and the second connection members are disposed at positions accessible from front sides of the plurality of uninterruptible power supply modules, and the second connection members each have a bent shape so as to avoid the fastener members.
 8. The uninterruptible power supply according to claim 1, wherein at least one of the second connection members includes at least one of holes and notches through which the fastener members pass.
 9. The uninterruptible power supply according to claim 1, wherein the second connection members are connected electrically to the first connection members to increase a capacity of current that flows between the input-side switches of the plurality of uninterruptible power supply modules and a capacity of current that flows between the output-side switches of the plurality of uninterruptible power supply modules.
 10. An uninterruptible power supply comprising: a plurality of uninterruptible power supply modules including input-side switches into which AC power is adapted to be input from an AC power source, power converters connected to the input-side switches, and output-side switches that output AC power received from the power converters; first connection members that connect the input side-switches of the plurality of uninterruptible power supply modules to each other and that connect the output-side switches of the plurality of uninterruptible power supply modules to each other; and second connection members connected electrically in parallel to the first connection members and stacked on the first connection members, wherein the first connection members and the second connection members are disposed at positions accessible from front sides of the plurality of uninterruptible power supply modules, the plurality of uninterruptible power supply modules includes a first uninterruptible power supply module, a second uninterruptible power supply module, and a third uninterruptible power supply module, adapted to be disposed in order from the AC power supply side, the first connection members and the second connection members form a first module input-side connection member and a first module output-side connection member, connected electrically to the input-side switch and the output-side switch of the first uninterruptible power supply module, a second module input-side connection member and a second module output-side connection member, connected electrically to the input-side switch and the output-side switch of the second uninterruptible power supply module, and a third module input-side connection member and a third module output-side connection member, connected electrically to the input-side switch and the output-side switch of the third uninterruptible power supply module, and each of the first module input-side connection member and the first module output-side connection member includes one first connection member and two second connection members, each of the second module input-side connection member and the second module output-side connection member includes one first connection member and one second connection member, and each of the third module input-side connection member and the third module output-side connection member includes one first connection member.
 11. The uninterruptible power supply according to claim 10, further comprising a plurality of input-side connection plates including a first input-side connection plate, a second input-side connection plate, and a third input-side connection plate to connect electrically the first connection members and the second connection members to the input-side switches of the plurality of uninterruptible power supply modules, wherein the first input-side connection plate connects electrically the AC power source and the one first connection member of the first module input-side connection member, the second input-side connection plate connects electrically the one first connection member of the first module input-side connection member and the one first connection member of the second module input-side connection member, and the third input-side connection plate connects electrically the one first connection member of the second module input-side connection member and the one first connection member of the third module input-side connection member, and the one second connection member of the second module input-side connection member connects electrically the second input-side connection plate and the one first connection member of the second module input-side connection member, one of the two second connection members of the first module input-side connection member connects electrically the first input-side connection plate and the one first connection member of the first module input-side connection member, and another of the two second connection members of the first module input-side connection member connects electrically the first input-side connection plate and the second input-side connection plate to be staked on the one of the two second connection members of the first module input-side connection member.
 12. The uninterruptible power supply according to claim 11, further comprising a plurality of output-side connection plates including a first output-side connection plate, a second output-side connection plate, and a third output-side connection plate to connect electrically the first connection members and the second connection members to the out-side switches of the plurality of uninterruptible power supply modules, wherein the first output-side connection plate connects electrically a load and the one first connection member of the first module output-side connection member, the second output-side connection plate connects electrically the one first connection member of the first module output-side connection member and the one first connection member of the second module output-side connection member, and the third output-side connection plate connects electrically the one first connection member of the second module output-side connection member and the one first connection member of the third module output-side connection member, and the one second connection member of the second module output-side connection member connects electrically the second output-side connection plate and the third output-side connection plate, one of the two second connection members of the first module output-side connection member connects electrically the first output-side connection plate and the second output-side connection plate, and another of the two second connection members of the first module output-side connection member connects electrically the first output-side connection plate and the second output-side connection plate to be staked on the one of the two second connection members of the first module output-side connection member.
 13. The uninterruptible power supply according to claim 1, wherein the at least one of the second members and at least one of the first connection members on which the at least one of the second members is stacked are arranged to form a gap therebetween in which the fastener members are arranged. 